Embrittlement of 5083 alloy by liquid gallium

The effect of grain boundary precipitates on the embrittlement of 5083 alloy solutionized, aged at 150°C for various periods and coated with liquid Ga was investigated by means of tensile test and microscopy. Ga coated 5083 alloy fractures along grain boundaries. The shorter the aging time, the lower the fracture stress of Ga coated alloy, though ultimate tensile strength of the alloy uncoated. is independent of the aging time. When the alloy was held at 35°C for various periods after Ga coating, the fracture stress becomes to be zero after a critical holding period tf. A relation between fracture stress σf and holding time t is expressed as σf=σf0-k•t1/2, where σf0 and k are constants.